If unbridled Mustang enthusiasm were heat, you could toast marshmallows off John Coletti from 50 feet away. Coletti is Ford's Special Vehicle Engineering manager, and the thermonuclear boss behind the baddest-asp production Cobra, yet.

Over dinner, Coletti boldly suggested a Motor Trend showdown between his car and a C5 Corvette. Sounds like a fairer matchup is with a Viper GTS.This R-version of the venerable Cobra has a monster engine, hunkered-down suspension, sticky tires, bigger brakes and wheels, Recaro buckets, and exterior aero pieces to keep it from flying at its quoted 170-mph top speed.

Ford's fire-breather is motivated by a 5.4-liter/385-horsepower high-revving (6500-rpm redline) DOHC V-8 with 385 pound-feet of torque. To shoehorn this howler into the regular Cobra's 4.6-liter/316-horsepower V-8's spot, new engine mounts and a lowering crossmember afford an extra 12 millimeters of clearance. But even so, the hood, with its bulging blister, barely closes over the honking, high-flow intake manifold.Exhausting the spent gasses are stainless, short-tube headers, Cobra catalysts, a Bassani X-pipe, and three Borla mufflers. Said mufflers rumble out of dual oval outlets that exit on both sides in front of the rear tires. The side exhaust enables the installation of a 21-gallon fuel cell across the rear for race-day romps.